FBMC Design and Implementation

Whereas Chapter 7 introduced the general multicarrier waveform theory and various alternative orthogonal waveforms, the focus in this chapter is on effective practical implementation schemes for the needed filterbanks, with main focus on the FilterBank MultiCarrier with Offset-QAM subcarrier modulation (FBMC/OQAM) case. In the first part, effective modulation-based uniform filterbank structures are used, and the designs are defined by the lowpass prototype filter. Two alternative paths are considered. The first approach starts from continuous-time formulation of the prototype filter responses, which are then discretized. Alternatively, the design problem can be formulated as a lowpass digital filter optimization problem with additional constraints to guarantee the orthogonality of subcarriers. While introducing the effective filterbank structures, the main emphasis is on the polyphase FilterBank (FB) model, but the lattice structure and lapped transform-based structure are briefly introduced as well.